cshum/imagor
Imagor
Imagor is a high-performance image processing server and Go library that functions as an on-demand image proxy. It provides a secure transformation API for resizing, filtering, and optimizing images, as well as a tool for generating static thumbnails from video files.
The system distinguishes itself by using a demand-driven processing engine to handle large images without loading entire files into memory. It features cryptographic request signing to prevent unauthorized URL tampering and employs header-based format negotiation to automatically serve the most efficient image format supported by a client's browser.
The project covers a broad range of capabilities, including region of interest detection, watermarking, and pluggable storage backends. It also manages resource lifecycles through concurrent data streaming and provides security measures such as input path sanitization to prevent cross-site scripting.
The server includes an HTML interface for rendering landing pages and upload forms.
Features
- Image Processing APIs - Provides a self-hosted API for programmatic image manipulation including resizing and filtering.
- High-Performance Image Engines - Provides a high-performance image processing engine that manages memory and concurrency for large assets.
- Image Transformation Proxies - Functions as an on-demand proxy generating optimized image versions via URL parameters for different devices.
- Dynamic Image Optimization - Performs runtime resizing and transcoding based on browser capabilities to optimize web delivery.
- Go Image Processing Libraries - Provides a programmatic Go library for high-performance image manipulation and filtering.
- Image Processing and Manipulation - Implements high-performance image decoding, encoding, and manipulation using libvips.
- Libvips Bindings - Utilizes libvips bindings for demand-driven, streamed image operations to minimize memory usage.
- URL-Driven Image Transformations - Provides a system for real-time image modification based on parameters embedded in the request URL.
- Image Processing Servers - Implements an HTTP server that applies image transformations via URL parameters using libvips.
- Request Signature Verification - Uses HMAC cryptographic signatures to verify request authenticity and prevent URL tampering.
- Secure Image Delivery - Secures image delivery using signed URLs and input sanitization to prevent unauthorized manipulation and exploits.
- Request Signing - Validates incoming requests using HMAC signatures to prevent unauthorized manipulation of image transformation parameters.
- Runtime Format Negotiation - Analyzes browser request headers to automatically serve the most efficient image format supported by the client.
- Cloud Storage Image Loaders - Provides handlers for loading source images from cloud object stores, remote hosts, or filesystems.
- Seekable Stream Buffering - Wraps non-seekable data sources in memory buffers to allow backward seeking during image processing.
- Pluggable Storage Backends - Decouples image processing logic from physical sources using a common interface for various storage providers.
- Concurrent Stream Buffering - Implements high-performance concurrent buffering to allow multiple readers to access a single data stream.
- Custom Processing Pipelines - Allows registering modular image manipulation functions that can be chained together in a processing pipeline.
- Image Watermarking - Supports applying visual markers and watermarks to images for branding and protection.
- Video Frame Extractors - Extracts static image frames from video files to create preview thumbnails.
- Automatic Format Negotiation - Automatically serves the most efficient image format supported by the client's browser headers.
- Image Processing - Provides a fast image processing server.
